Field of the Invention
The invention relates to an integrated circuit configuration for reducing current consumption, having a multiplicity of function units which are connected to one another through bus lines, wherein data and/or addresses and control signals are transmitted over the bus lines.
Current saving modes are increasingly demanded in integrated circuit configurations, especially LSI (large-scale integrated) microprocessors and microcontrollers. Siemens Microcontrollers Data Catalog 1990 describes the Siemens 16-bit microcontroller SAB 80C166 on page 465 ff.. It has a current-saving mode which is activated by software, during which a supply voltage of only more than 2.5 V is needed. FIG. 3 on page 471 shows a block circuit diagram of that microcontroller. As can be seen therein, a multiplicity of internal function units are connected to the central processor through respective bus lines.
The disadvantage of such internal function units, which are discussed in more detail below with regard to FIG. 1, is that they are permanently connected to the bus of the central processor and thus process signals present on bus lines that lead from and/or to the central processor. In CMOS circuits, current is consumed precisely due to such switching of the signals and is dictated partly by cross current but primarily by charge reversal of load capacitors.